Bram van den Heuvel wrote:
Given news wrote:

Have you checked Amazon, NAPA, or farm supply stores like Tractor
Supply,
Rural King, or Orscheln? The first one that pops up at Amazon is $35.

I admit I'm running off of fear since all the Toyota guys say that you must
use either Amsoil or Royal Purple or Redline GL4 75W90 in the manual
transmission.

Well, then buy that.

There are plenty of cheaper GL4 oils out there. Most of the cheaper ones
are not synthetics. They will not have sulfur additives that will damage
nonferrous metals the way GL5 does. But, they also will not last as long
and be as slick as the synthetics.

The synthetics are much more expensive. If they are formulated well, it
is possible to make synthetics that cling to surfaces better, don't degrade
as much with time, and keep junk in solution better. The Red Line will
definitely do these things. Do you need any of these characteristics?
I don't know, but it sounds like "all the Toyota guys" think you do.

Even the Royal Purple 75W90 gear oil is $60 per gallon.
https://skspeed.com/royal-purple-013...-gl-5-1-quart/

That's not particularly expensive for a synthetic oil.

All I want to know is what's so special about these gear oils that they
cost $60 to $70 a gallon (where I need about a gallon)?

They are synthetic oils, actually genuine synthetics where the base oil
materal has been made from a pure short-chain stock. Whereas natural
petroleum oils are always going to be a mixture of paraffins, napthas,
and napthalines no matter how well they are purified, these are pretty damn
pure. But, it's more expensive to make an oil from ethylene gas than it is
to take an existing oil and purify it.

If you think $70/gal is expensive, you should see what the high purity
instrument oils for rebuilding speedometers costs.

Looking up the gear oils, I find technical information but nothing answers
my question which is why I asked here.

A study of automotive gear lubes
http://www.technilube.com/brochures/...hite_paper.pdf

The answer is mostly that a dollar isn't worth a dollar anymore. Back when
gas was a quarter a gallon, gear oil cost about 25 times what gas did. Today
gas is $2/gal. and gear oil costs about 25 times what gas does.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."